The present invention relates generally to automotive lamps. More specifically, the present invention relates to bi-functional automotive headlamps.
Generally, conventional automotive forward lighting systems, or headlamp systems, are required to provide lighting to meet two (2) distinct functions. First, a headlamp system must provide illumination adequate for a normal driving condition in which a vehicle and its driver are likely to encounter other vehicles on the roadway, paricularly such vehicles traveling in the opposite direction on the same roadway in the form of oncoming traffic. Under this condition, an automotive forward lighting system must provide illumination that is sufficient to safely illuminate the area in front of the vehicle, but not be aimed in such a direction that the illumination distracts, or even temporarily blinds, the drivers of oncoming traffic. The illumination produced by a headlamp system to meet this first function or requirement is commonly referred to as xe2x80x9clow beam.xe2x80x9d Second, an automotive forward lighting system is required to provide additional illumination that can be utilized by a vehicle driver when additional lighting is necessary, but, for a variety of possible reasons, the concern over causing temporary discomfort to drivers of oncoming vehicles, is reduced or non-existent. The illumination typically provided under this function is generally directed slightly higher than that produced by a low beam, and generally more directly in front of the driver of the vehicle. The illumination produced by a headlamp system to meet this second function or requirement is commonly referred to as xe2x80x9chigh beam.xe2x80x9d
Because a headlamp system""s ability to provide adequate illumination, under both the low beam and high beam functions, is so critical to the safety of the occupants not only of that vehicle, but also of other vehicles on the roadway, numerous government laws and regulations dictate the exact requirements that an automotive forward lighting system must meet for both its low beam and high beam functions. Thus, automotive headlamp systems must be designed to meet such strict requirements for both the low beam lighting function as well as the high beam lighting function.
Several automotive forward lighting system configurations are well known in the industry. For example, a commonly used configuration utilizes four (4) total headlamps, with two (2) positioned on each side of the front end of the vehicle. Generally, with this type of configuration, one (1) headlamp on each side of the vehicle is used to accomplish the low beam function. The high beam function may then be accomplished by, in some designs, utilizing the remaining two (2) headlamps on either side of the vehicle to provide additional illumination, or supplement the light produced by the first two (2) headlamps. In this type of configuration, all four (4) headlamps are illuminated to accomplish the high beam function. Alternatively, the four (4) headlamp system configuration may simply utilize two (2) headlamps, again one (1) on each side of the vehicle, for the low beam function and the remaining two (2) headlamps for the high beam function. In this type of configuration, only two (2) headlamps are illuminated at any given time, but four (4) headlamps are necessary to meet the dual functions and requirements of low beam and high beam.
Unfortunately, the four (4) lamp design generally described above contains several disadvantages. For example, such designs are expensive to produce as they require more headlamp units per vehicle. Additionally, these systems are generally more expensive because the parts associated with such systems (e.g., housings, retainers, brackets, screws) are either more complicated than would otherwise be necessary, or simply more of such parts are required for the multi-lamp configuration. Performance of such a system can also be an issue. Specifically, in a four (4) lamp system with only two (2) headlamps illuminated for the low beam function and only the other two (2) headlamps illuminated for the high beam function, when switching from one beam pattern to the other (either low beam to high beam or high beam to low beam) in such a system, the illumination pattern may change dramatically in an instant. Such a dramatic change is undesirable as it may briefly confuse or disorient the vehicle""s driver. Also, when multiple lamps are used to accomplish the low beam and high beam lighting requirements, respectively, a color difference can occur between the low beam light and the high beam light. Such a color difference is not aesthetically pleasing or desirable.
Additionally, a four (4) lamp system may present safety concerns as it is possible during cold weather conditions for icing to occur on the outer surface of a headlamp if that headlamp is not illuminated continuously. Thus, a switch to high beam during such conditions may not provide the necessary illumination as the high beam headlamps have malfunctioned due to ice formation. Furthermore, the four (4) lamp system generally requires more space which can be problematic on the front end of a vehicle where the space available for any one assembly is at a minimum. Thus, these four (4) lamp systems, which can be relatively large, tend to limit design options for a vehicle""s front-end. Moreover, the overall appearance of the four (4) lamp system, which again is generally larger and contains more parts, is considered by some as undesirable, especially for vehicles in which a sleek, aerodynamic appearance is important. Finally, because multiple lamp systems utilize more lamps, usually four (4) compared to two (2), they generally require and consume more electrical energy.
In order to attempt to address the shortcomings of the four (4) headlamp system, two (2) headlamp systems have been developed and are well known in the art. These two (2) headlamp systems utilize only a single lamp on each side of the front end of a vehicle, with each of those lamps performing both the low beam and high beam lighting functions. For ease of reference, the term xe2x80x9cbi-functionalxe2x80x9d is used herein to describe such a single automotive headlamp unit that is capable of producing both a low beam lighting pattern and a high beam lighting pattern. One example of a bi-functional system used in the past is a system that utilizes two (2) headlamps, each with two (2) light bulb filaments. The different filaments of each lamp are utilized independently to accomplish the low beam function and the high beam function, respectively. Thus, while having the appearance of only utilizing two (2) lamps, in essence, this type of forward lighting system still utilizes four (4) light sources. This type of system also has disadvantages. The specialized bulbs utilized for this type of system can be overly complex and expensive to both manufacture and replace. Additionally, replacement may be necessary if xe2x80x9cburn-outxe2x80x9d occurs for the bulb filament accomplishing one (1) lighting function, even though the filament for the other function is still in working condition.
Another attempt to accomplish bi-functionality for a two (2) lamp forward automotive lighting system that is known in the industry involves lamps that allow the light source to be repositioned relative to the lamp reflector. Generally, in order to accomplish high beam functionality the light source, or light bulb, is repositioned relative to the headlamp reflector thus changing the direction of the emitted light. While bi-functionality is accomplished by this system, it is necessary to closely control the critical tolerances involved with repositioning the light source. Such control can be difficult and expensive to accomplish initially, and may be even more difficult to control over the life of the vehicle. Subtle changes in the positioning of the light source can result in undesirable shifts in the vehicle lighting pattern for either the low beam or high beam, or even both. Thus, the reliability of such a system is suspect. Furthermore, adjusting the xe2x80x9caimxe2x80x9d of such an assembly, which is necessary both prior to a vehicle being put into use by a consumer and, under some circumstances, during the life of the vehicle, can be difficult.
Therefore, it is desired to provide a bi-functional automotive forward lighting system which utilizes only two (2) headlamps that each accomplish both the low beam and high beam lighting functions. It is further desired that such a bi-functional headlamp system provide an assembly which reliably meets the forward lighting requirements of a vehicle, while not being overly complex or expensive to manufacture. It is additionally desired that such a system provide a means for adjusting headlamp aim that is not overly complicated or cumbersome to use.
The present invention provides a bi-functional automotive forward lighting system, that utilizes only two (2) headlamps, wherein bi-functionality is accomplished by pivoting the headlamp reflector about three (3) pivot points arranged in a triangular manner. The invention comprises a headlamp reflector which includes three (3) mounting bosses, arranged in a triangular fashion, on the rear surface of the reflector. A pivot socket is fixedly attached to each mounting boss. Additionally, a ball pivot adjusting screw is movably secured within two (2) of the three (3) pivot sockets, while an actuator ball pivot is movably secured within the third pivot socket. An actuator is attached to the actuator ball pivot in a manner that permits linear motion of the actuator, which is also fixedly attached to a lamp housing. The invention further comprises a vertical adjuster plate and a reflector plate.
Initial horizontal and vertical aim of the invention for the low beam function may be accomplished by adjustment of one (1) of the ball pivot adjusting screws for each direction of aim.
Once the initial adjustments are completed, the headlamp is set for low beam operation. In order to achieve bi-functionality and accomplish the high beam function, the headlamp reflector is simply moved by adjustment of the actuator attached to the actuator ball pivot. Due to the triangular arrangement of the pivot points, movement of the actuator will cause the headlamp reflector to adjust in both the horizontal and vertical directions. This slight adjustment of the headlamp reflector for each of the two (2) lamps of the invention allows the headlamp assembly of the invention to accomplish the high beam function.